TM 55-203
Safety valve (tank car). A valve attached to the dome
rod and working parts of some form of engine. In a
of a tank car to prevent excess pressure due to the
brake cylinder, the piston transfers the pressure of
vapors arising from volatile liquids.
the air to the foundation brake gear.
Safety vent. An opening formed by a hollow casting or a
R1, R2, R3, and R4. (See Designations )
piece of pipe inserted in the dome of a tank car. It
Release valve (airbrake). A cock for reducing air
is used on cars carrying products which are
pressure in the auxiliary reservoir when the
nonflammable or do not give off flammable vapors.
locomotive is detached or when the apparatus is out
Shank (coupler). That part of a coupler between the butt
of order, so as to release or "bleed" the brakes.
and the head.
Reservoir (airbrake). A cylindrical container.
Main
Sheathing. The covering around the sides and ends of
reservoirs of large capacity are placed under all
a car Tongue and groove lumber is used on wooden
motorcars having air compressors; auxiliary
cars and steel plates on all steel cars. On steel-
reservoirs are placed under all cars equipped with
frame cars, horizontal wood sheathing is generally
automatic airbrakes. In freight service, a cast-iron
applied
auxiliary reservoir is connected directly with the
brake cylinder and triple valve.
car body or truck on each side of the center plate to
Reservoir pipe (airbrake). Also called air pipe and
steady the car and prevent excessive rocking.
discharge pipe The pipe conveying the air from the
air compressor to the main reservoir.
Side frame. The frame which forms the side of a car
body or a truck.
Ridge pole. A longitudinal member in the center of a
roof, supported by the carllnes or rafters (of wooden
Side sill. The outside longitudinal members of the
cars), on which the roof boards rest.
underframe.
Rocker side bearing. A device somewhat similar to the
Skirt. An extension 'of the sheathing below the side sill
roller side bearing. Instead of rollers, rockers are
on passenger cars.
used, which offer a gradually increasing resistance
to the lateral motion of the bolster and force it to
Spring plank. A transverse member underneath a truck
return to its normal position at all times.
bolster on which the bolster springs rest.
Roller bearing. The general term applied to a group of
bearings which depend upon the action of a set of
or collar attached to the side and end sills to receive
rollers to reduce rotational friction.
the end of a stake which supports the side or
confines the load. Also, used near the top of
Roller side bearing. A side bearing fitted with rollers to
gondola cars to receive the stakes used in applying
reduce friction.
a coke rack or other appliance for increasing the
depth of the car.
Roof handhold (boxcars and stock cars). An iron bar
bent to a required shape and fastened to the roof to
Stringer. A floor nailing strip or a steel member which
be grasped when ascending the ladder at the end of
acts as a support for a nailing strip.
the car.
Swivel-butt coupler. A coupler in which the solid shank
Running board. A plane surface made of boards or a
has been replaced by a swivel-butt casting
special metal structure on which trainmen may walk.
connected to the coupler itself by means of a pin.
It may be placed on the roof of the caboose,
This arrangement permits the coupler head to swivel
boxcars, stock cars, refrigerator cars, and covered
without causing eccentric loads.
hopper cars, and at the sides of tank cars. (No
longer required by AAR rules in CONUS. )
Tank dome. A vertical cylinder attached to the top of a
tank car. It permits the tank proper to be filled to full
cubic capacity, which would be impossible if there
protects against an accumulation of excess
were no dome.
pressure.
Tank head. The end sheet of a cylindrical tank.
Safety valve (high-speed brake). A relief valve applied
to the brake cylinders of cars which are not
Tape size.
Circumference of the wheel at the wheel
equipped with a high-speed reducing valve to
tread.
relieve the brakes from excessive pressure.
Trainline. The complete line of airbrake, air signal, or
steam heat pipes in a railroad train
Glossary 5
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